THE STRUCTURE OF FREE-MARTIN GONADS 



95 



Particularly large collections are found around blood-vessels 

 and at the 'carrefours/ that is, in the intervals between the sec- 

 tions of three or more seminiferous tubules. These large areas 

 may be observed with the unaided eye. They are not isolated 

 collections, but are continuous with the interstitial cells in the 

 stroma strands between the tubules. In cases 44 and^H-46 

 (fig. 12, i) the interstitial cells are moderately numerous. 





Fig. 12 Portion of the sex-cord region of free-martin gonad, H-46. i, inter- 

 stitial cells in a connective-tissue stroma; s, seminiferous tubule showing the 

 nuclei of the supporting epithelial syncj^tium arranged into a single layer closely 

 applied to the wall of the tubule. From the inner end of each nucleus extends 

 a strand of cytoplasm toward the center of the tubule. Note absence of germ 

 cells. X 307. 



A detailed examination of the interstitial cells in case H-37 

 (fig. 11, i) shows much variation in their structural j^features. 

 There is much variation in size, the majority being many times 

 larger than the interstitial cells of the normal testis of the adult. 

 In shape, the majority are irregularly polygonal. The eccen- 

 trically placed nucleus is large, somewhat vesicular, and contains 

 scattered chromatic granules. The structure of the cytoplasm 

 also varies in the different types of cells. In a small proportion 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 33, NO. 1 



